jacoby, while the e200 and c200 are similar, they are not the same. The trick Rockbox uses to disable the database refresh on the e200s doesn't work here - at least not on most c200 original firmware versions (see
this commit message for details; the developer of this gave me a patched bootloader to try on my c200 before the commit).
If I understand correctly the e200 OF sets a bit at disconnect from USB that something's changed and a database refresh is needed but only actually refreshes it at next boot. To disable this mechanism, the Rockbox bootloader can unset that bit and the e200 OF doesn't get to know that things changed. On most c200s the database refresh starts as soon as you disconnect from USB, there's no chance for the Rockbox bootloader to interrupt this process.
P.S.: For some reason I started to believe (something I read?) that later c200 firmware versions handle these things more like the e200 original firmware. Does someone know more?